acting weird

One of my friends complained that her husband doesn't like to be seen around her. Whenever they go out together, he feels a bit uneasy especially when they run into his friends. She feels that he doesn't like her anymore but they have been together for almost ten years. I personally don't think he thinks that but what is a better reason for him acting like that? Have you experienced it before or do you know someone who has? Why?

Are there any mistakes?
Thanks.